#pragma once

#include <QString>
#include <QList>
#include <QHash>
#include "ast_basic.h"
#include "libsyntax_global.h"

namespace ast_gen
{
	class TokenAccess;

	/**
	 * @brief 解析上下文
	 */
	class SyntaxElement {
	public:
		virtual ~SyntaxElement() = default;
		/**
		 * 绑定表达式实体.
		 * 
		 * \return 表达式实例
		 */
		virtual std::shared_ptr<const ast_basic::Expression> bindExpression() const = 0;

		/**
		 * @brief 类型标记
		 * @return
		 */
		virtual int typeMark() const = 0;

		/**
		 * 是否属于匿名节点.
		 *
		 * \return 匿名标志
		 */
		virtual bool isAnonymous() const = 0;

		/**
		 * @brief 文件路径
		 * @return
		 */
		virtual QString path() const = 0;

		/**
		 * @brief 元素签名，如果是匿名元素返回空字符串
		 * @return
		 */
		virtual QString signature() const = 0;

		/**
		 * @brief 获取父元素
		 * @return 未设置parent，返回nullptr
		 */
		virtual std::shared_ptr<const SyntaxElement> parent() const = 0;
		virtual void setParent(std::shared_ptr<const SyntaxElement> inst) = 0;

		/**
		 * @brief 定义元素自身的Token集合
		 * @return
		 */
		virtual QList<std::shared_ptr<const TokenAccess>> selfTokens() const = 0;
		virtual void cacheLoad() = 0;
	};

	/**
	 * @brief 语法元素整理访问接口
	 */
	class LIBSYNTAX_EXPORT ElementAccess {
	private:
		std::shared_ptr<const SyntaxElement> peers;

	public:
		ElementAccess(std::shared_ptr<const SyntaxElement> point);

		std::shared_ptr<const SyntaxElement> element() const;

		QList<std::shared_ptr<const ElementAccess>> children() const;

		/**
		 * @brief 获取该元素下所有Token定义
		 * @return
		 */
		virtual QList<std::shared_ptr<const TokenAccess>> tokens() const;
	};

	class LIBSYNTAX_EXPORT TokenAccess {
	private:
		std::shared_ptr<const ast_gen::SyntaxElement> element_bind;
		std::shared_ptr<const lib_token::Token> token_store;

	public:
		TokenAccess(std::shared_ptr<const ast_gen::SyntaxElement> elm_inst, std::shared_ptr<const lib_token::Token> token_inst);
		virtual std::shared_ptr<const ast_gen::SyntaxElement> bind() const;
		virtual std::shared_ptr<const lib_token::Token> token() const;
	};

	/**
	 * @brief 根元素定义
	 */
	class LIBSYNTAX_EXPORT GlobalElement : public SyntaxElement, public ast_basic::ExpressionContext {
	private:
		QString names_store;
		QHash<QString, std::shared_ptr<const SyntaxElement>> node_cache;

		std::shared_ptr<ast_basic::Expression> bind_exprs = std::make_shared<ast_basic::ExpressionElement>(nullptr);

	public:
		static GlobalElement* UniquePtr;
		GlobalElement(const QString& name);

		virtual void clearCache();
		virtual void appendToCache(std::shared_ptr<const ast_gen::SyntaxElement> named_node);
		/**
		 * @brief 通过节点签名获取定义节点
		 * @param signature 完全签名
		 * @return
		 * @throws 没有指定节点抛出异常
		 */
		virtual std::shared_ptr<const ast_gen::SyntaxElement> getNamedNodeBy(int type, const QString& signature) const;

		virtual void addChild(std::shared_ptr<ast_gen::SyntaxElement> citem);

		// ParseElement interface
	public:
		virtual int typeMark() const override;
		virtual bool isAnonymous() const override;
		virtual QString signature() const override;
		virtual QString path() const override;
		virtual std::shared_ptr<const SyntaxElement> parent() const override;
		virtual void setParent(std::shared_ptr<const SyntaxElement> inst) override;
		virtual QList<std::shared_ptr<const TokenAccess>> selfTokens() const override;

		// 通过 SyntaxElement 继承
		virtual std::shared_ptr<const ast_basic::Expression> bindExpression() const override;
		virtual void cacheLoad() override;
	};
}